These are likely identifiers for a specific website or a "sub-community" (subcom) within a larger hosting network. It suggests a repository of media files.
: Despite TV's rise, movie theatres remained high-glamour destinations for major releases featuring icons like Marilyn Monroe.
This is often a timestamp or a unique database ID. In many video platforms, "start=" followed by a number indicates the specific second or millisecond where a clip begins, or simply the numerical index of the file in a server.
The file was edited, remixed, and "stitched" thousands of times.